1. Field of the Invention
The present invention relates to an electric toothbrush which provides improved brushing in gaps between teeth.
2. Description of the Related Art
Conventionally, several ways of brushing teeth have existed. One way of brushing is by manually brushing with a toothbrush (a so called hand brush), which has many hairs thereon. With this toothbrush, there are two major methods for effectively brushing teeth, one is a "Scraping Method" in which the toothbrush, whose tips of the hairs of the brush contact the user's teeth, is reciprocated. Another method is a "Bass Method" in which the toothbrush, whose tips of the hairs of the brush contact a bonder between the teeth and gums by inclining the head section of the toothbrush about 45 degrees, and vibratins the head back and forth.
Another known way of brushing teeth is with an electric toothbrush in which a hand brush is attached to a drive section having a motor therein so as to linearly reciprocate the brush.
When using the hand-held type of brush, despite the known effective methods for brushing teeth such as the Scraping Method, the Bass Method, etc., it is difficult to master these methods, and there is an individual difference in brushing technique so that all users cannot brush equally as well even when learning the same techniques. The number of people who cannot brush effectively far outnumber people who can brush well. It is especially difficult to remove food particles on teeth which are stuck in gaps between teeth, on borders between the teeth and gums and concave sections of teeth.
Electric toothbrushes are also known which can change between the Scraping Method and the Bass Method (e.g. Japanese Provisional Patent Publication (Kokai) Gazette No. 61-103404). In this electric toothbrush, however, rotary movement of a motor is converted to reciprocating movement, so that a large vibration is transmitted to a drive section and user the feels uncomfortable. Further, the brushing direction of the toothbrush is fixed, so that there are some portions of the mouth which are difficult to brush.